1. Technical Field
The present invention relates to an ink composition with a minimal change in its properties over a long period of time and with high reliability in terms of discharge stability, etc.; an ink cartridge, a recording method, a recording system and an article recorded using that ink composition; and a pigment dispersed liquid constituting that ink composition.
2. Related Art
Conventionally, techniques such as heat-treating a resin-containing pigment dispersion, or heating with the addition of a basic substance have been developed. A pigment dispersed liquid obtained through that kind of heat treatment has been utilized for ink compositions (as disclosed in JP-A-2000-345093, JP-A-2003-64292, JP-A-2003-26972, JP-A-2003-253178, JP-T-2003-535949 and others).
However, when an ink composition made using the conventional techniques is left unused for a long period of time, its viscosity can change, which affects inkjet discharge performance. In particular, ink compositions containing a high concentration of pigments have an especially strong tendency to do so.